Bob's Bar-B-Que   The malts. The barbecue (especially the fall-apart-on-the-fork baby back ribs). The mixed plate. The hibachi chicken. The plain old-fashioned burgers. There's a reason why there's always a gaggle of people under the orange sign at Bob's. There are a few tables out front, or take your plate lunch home.  1366 Dillingham Blvd. 842-3663. 6 a.m.-10 p.m. Mondays-Thursdays; 6 a.m.-11 p.m. Fridays-Saturdays; 7 a.m.-10 p.m. Sundays. No reservations. VS, MC, AX. No checks. $.